diff --git a/drivers/infiniband/core/fmr_pool.c b/drivers/infiniband/core/fmr_pool.c
index 86a3b2d401db..8926a2bd4a87 100644
--- a/drivers/infiniband/core/fmr_pool.c
+++ b/drivers/infiniband/core/fmr_pool.c
@@ -394,20 +394,12 @@ EXPORT_SYMBOL(ib_destroy_fmr_pool);
  */
 int ib_flush_fmr_pool(struct ib_fmr_pool *pool)
 {
-	int serial;
-
-	atomic_inc(&pool->req_ser);
-	/*
-	 * It's OK if someone else bumps req_ser again here -- we'll
-	 * just wait a little longer.
-	 */
-	serial = atomic_read(&pool->req_ser);
+	int serial = atomic_inc_return(&pool->req_ser);
 
 	wake_up_process(pool->thread);
 
 	if (wait_event_interruptible(pool->force_wait,
-				     atomic_read(&pool->flush_ser) -
-				     atomic_read(&pool->req_ser) >= 0))
+				     atomic_read(&pool->flush_ser) - serial >= 0))
 		return -EINTR;
 
 	return 0;